HP 3562A, Service Manual

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MOD E L 3562A
REQG B l
lDG D B R l
B I0320l
IRQ320l
B RDSE lH
C I RC U I T D ESCRI PT I O N S
Request global bus, active low. A signal from the I/O seq uencer to the
sequence decoder and the global bus handshake circ u it req uesting control
of the global bus.
Load global data bus register, active low. T h is signal loads data from the
global data bus into the read registers. It is activated when the FFT is granted
memory access and G DS L (global data strobe) becomes active (Iow) ..
Branch on I/O, active low. A signal from the test bit mux to the TMS320
m icroprocessor.
I nterrupt request to the TMS320 microprocessor, active low.
Board select, active h igh. Signal created by the identity comparator in the
FFT interrupt circu it. This signal indicates that the system CPU is add ress­
ing the FFT board.
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